(1) Field of the Invention
This invention relates to a sewing device for use in multi-needle sewing machine, and more particularly to a sewing device comprising a needle unit with a plurality of needles, a presser foot unit with a plurality of presser feet, a throat plate unit with a plurality of throat plates, a feed dog unit with a plurality of feed dogs, and a looper unit with a plurality of loopers.
(2) Prior Art
In the known sewing device for use in multi-needle sewing machine, an interval between presser feet, an interval between throat plates, and interval between feed dogs and an interval between loopers are respectively set according to each interval between needles (hereinafter called as "needle interval"), and said needle interval and each of said intervals are not variable. Accordingly, when necessary to change the needle interval, it is required to replace each component or unit such as needle bed, presser foot unit according to a new specification taking the place of the original specification.
Needless to say, it is quite uneconomical for an user to have varieties of components or units such as needle bed, presser foot unit always available or ready according to the difference of the needle interval for which replacement is supposed to be necessary. Further, it is not so easy to keep those components or units well-maintained even when they are out of use. Furthermore, it is neither efficient nor easy to change the needle interval by replacing each component or unit every time of such change.
From the standpoint of a manufacturer, in order to meet as soon as possible the request from user, it is necessary for them to manufacture every specification of components and units and to assort those components in the store house.
Moreover, since each component or unit such as needle bed, presser foot is not a so-called general purpose article but and article for exclusive use which is not suitable for mass production and requires rather high accuracy and high cost in their production, it is difficult to provide said component or unit at moderate price. Thus there exists a problem in that for both user and manufacturer the financial burden is too heavy.